The research is a continuation of research begun three years ago. The goal was to improve digital subtraction angiographic (DSA) image quality by incorporating classical tomographic imaging principles along with those of DSA. To a large extent, that goal has been realized except in the area of coronary angiography, where progress has been delayed due to the unexpectedly slow delivery of a moving focal spot x-ray tube. Yet progress in that area has been good. All other components of the real-time coronary artery tomography device ("Tomotron" system) have been fabricated and bench-tested successfully. It is proposed that our previous efforts be continued in four areas whose combined goal is to establish tomographic angiography as a useful and practically implementable clinical tool. First, optimum arteriographic image quality will be achieved by employing 3-D reconstruction algorithms specifically designed for reconstructing dilute vascular beds from limited angle projection data. Second, true 3-D volume reconstruction, free from the limitations that attend limited angle geometry, will be explored by developing a prototype volume CT scanner using a conventional intensifier and colled CCD array as the detector. Third, a unique, simple, real-time caligraphic display system adapted specifically for viewing 3-D vascular anatomy will be developed and tested. Lastly, the Tomotron system will be assembled and tested both on phantoms and animals. Optimization of imaging performance using this system will be a primary goal.